Interprétation des marqueurs de l'éthanol dans les cheveux (EtG et FAEE) en regard des paramètres sanguins usuels et de leurs fenêtres de détection

Considering the large scale of alcohol-associated problems, the diagnosis of excessive alcohol consumption is an important task from a medical and legal point of view. Major markers of ethanol consumption in hair are ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEE). Detection of EtG in hair is associated with excessive alcohol consumption, whereas a negative result does not unambiguously exclude the alcohol abuse. Investigations on the fatty acid ethyl esters (FAEE) can also be used to monitor excessive alcohol consumption. Four FAEE (ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) are the most suitable markers for the detection of heavy alcohol consumption and show differential concentrations in hair of children, adult teetotalers and social drinkers in comparison with FAEE concentrations found in hair of alcoholics. The Society of Hair Testing has provided guidelines for hair testing for chronic excessive alcohol consumption. This paper will review the difficulties in interpreting results, particularly when they are in contradiction between hair tests and usual blood (carbohydrate deficient transferrin) and liver function (Gamma GT or mean corpuscular volume) tests and will address several warnings versus the routine use of hair markers for documenting chronic excessive alcohol drinking. We have reviewed 49 cases during August 2011 and August 2012 where we have been asked to interpret both blood and hair tests. Several conflicting results were obtained and are discussed.